1. Field of the Invention
This invention relates to novel oxazinoindole and thiazinoindole derivatives, to processes for their preparation and to intermediates used in these processes. For convenience, further reference in this specification will be made to these compounds as oxazinoindole derivatives.
More specifically, the present invention relates to oxazinoindole derivatives possessing valuable pharmacologic properties. For example, these derivatives exhibit useful antidepressant properties at dosages which do not elicit undesirable side effects. Furthermore the present derivatives exhibit properties useful for the treatment and prevention of ulcers. The combination of these pharmacologic properties together with a low order of toxicity render the oxazinoindoles of the invention therapeutically useful.
2. Description of the Prior Art
Very little attention has been given to 1,4-oxazino-[4,3-a]indole derivatives prior to this disclosure. In the few reports that do exist, such as the reports by J. A. Elvridge and F. S. Spring, J. Chem. Soc., 2935, (1949) and W. R. Smith and R. Y. Moir, Can. J. Chem., 30, 411 (1952), the oxazinoindole derivatives are treated more in the manner of chemical curiosities. In these instances, the oxazinoindoles are distinguished readily from the compounds of this invention by having the pyran portion of their ring system at a higher oxidation state.